Boston Celtics center Robert Williams III will undergo an arthroscopic procedure on his left knee this week, causing him to require four to six weeks for recovery, sources told ESPN on Tuesday.
The procedure, expected to be Thursday, will come six months after Williams had left knee surgery to repair a torn meniscus.
The latest procedure is described as a "cleanup" and is expected to allow Williams to return to full strength early in the regular season, sources said.
Williams, who will turn 25 in October, returned for the Celtics' run to the NBA Finals and played with discomfort in the playoffs that caused him to miss seven games.